Recently, the miniaturization of semiconductor devices has progressed with the high integration or the like of integrated circuits, and consequently, in addition to high flatness, a high level reduction of surface defects has been required for semiconductor substrates (hereinafter, also simply referred to as substrates) such as semiconductor wafers (hereinafter, also simply referred to as wafers).
For the purpose of reducing such surface defects, polishing of the surface of substrates with a polishing composition including a water-soluble polymer, which is a component enhancing the wettability to semiconductor substrates, has been considered.
Such a polishing composition is described in, for example, Patent Literature 1. Patent Literature 1 describes a polishing composition including hydroxyethyl cellulose as a water-soluble polymer.
Surface defects having various sizes are present in a mixed manner on the surface of a substrate before polishing; however, with such a conventional polishing composition as described in Patent Literature 1, it is impossible to selectively remove surface defects having specific sizes. Accordingly, for example, in the case where a large number of surface defects having specific sizes are present on the substrate surface, or in the case where polishing is performed for the purpose of removing surface defects having specific sizes among the surface defects present in a mixed manner, there is a problem that it is impossible to sufficiently remove the surface defects having the targeted sizes with the polishing composition described in Patent Literature 1.